Overcoats in rotating disk perpendicular or longitudinal data storage applications are a challenging technology requiring management of materials properties on the nanoscale. In the past, overcoat technology included a simple, layer of carbon and an adhesion layer. Such simple structures are no longer able to address concerns of new technologies.
In emerging leading edge storage technologies such as heat assisted magnetic recording (HAMR), additional requirements for overcoat film characteristics include high thermal resiliency, control of optical characteristics (of bulk materials and interfaces) and thermal management. Management of the interface between the underlying transducer structure and overcoat system is of even greater importance due to the more demanding, higher temperatures experienced and the requirements of new plasmonic materials systems in the transducer structure. Simple overcoat/adhesion layer structures, as used in contemporary perpendicular storage transducer technology, cannot accommodate the increased requirements for film functionality in HAMR and may have limited extendibility in perpendicular data storage.